An arrangement for the production of stator housings, for electric motors, from aluminum die casting material is already known. To produce the laminated stator cores which are to have material cast around them, and to carry out the handling functions, several things are associated with the die casting machine, namely a pack forming station with a high-frequency furnace, a pivotable apparatus for the clamping of the laminations by means of inserted mandrel sleeves and a press for removing the mandrel sleeves from the finish cast stator housings with a water bath.
A gantry, with a carriage movable thereon and two gripping tongs capable of perpendicular movement on the carriage, namely a loading tongs and an unloading tongs, connects the clamping apparatus for the laminations with the die casting machine.
The punched laminations supplied by a first conveyor belt are tipped onto a mandrel sleeve at the pack forming station, weighed and the lamination assembly pressed together, if required, and brought by the conveyor belt first into the high-frequency furnace for preliminary heating and then to the pivotable clamping apparatus. The latter engages in the mandrel sleeve of the lamination assembly which is entered therein with the bore disposed vertically and pivots the assembly into a horizontal position relatively to the loading tongs of the gantry which tongs is in the position of readiness. The loading tongs, by means of a head piece the extension of which is displaceable into the bore of the mandrel sleeve, takes over the lamination assembly. When the carriage, with the two gripping tongs and the lamination assembly, moves over the mold of the die casting machine, it again remains in the position of readiness.
The casting operation and the subsequent cooling time for the castings take place during the steps described above. After the cooling time has elapsed, the lamination assembly, together with the stator housing which has been cast around it, is removed from the mold by means of the unloading tongs and then the new lamination assembly is placed in the mold by the loading tongs.
Subsequently the carriage returns to the pivotable clamping apparatus, to which the stator housing is delivered by the unloading tongs. After the subsequent cutting-off of the sprues and the casting residue from the stator housing and the transfer of the head piece from the unloading tongs to the loading tongs, the mandrel sleeve is pressed out of the bore in the stator housing in the press provided for this purpose.
While the finished stator housing and the casting residue with the sprues are taken away by a second and third conveyor belt, respectively, to a depositing area and to the melting furnace, respectively, the mandrel sleeve, removed from the bore in the finished stator housing, falls into a water bath. A fourth conveyor belt then returns the recooled mandrel sleeve to the pack forming station.
In order to provide for continuous operation of the die casting machine, this system, in addition to the two headpieces, of which one is situated in the casting mold and the other above the mold, in the region of the pivotable clamping apparatus or in an intermediate location between these two, requires six mandrel sleeves for each stator size to be cast. Apparatus such as a mandrel press, a cooling station with a water bath and a conveyor belt are also necessary for returning the sleeves into the preparation process.
The preparation process is carried out in locally separated part-steps along the supply conveyor belt. The individual incremental movements are time consuming, so that the cycle time of the die casting machine, which is becoming shorter and shorter with the use of relatively small electric motors, is not sufficient for all the manipulating functions.